Perform a study on "The Effects of Fertility on Changing Roles of Women and Men". The Contractor shall estimate, for couples, a simultaneous equations model of time allocation to market work, child care, housework, and leisure activities by men and women. This model will estimate the extent that shifts in activities of one spouse contrain or complement shifts in the other spouse's activities, each responding to changes in predetermined numbers and ages of children. Related analysis will determine the impacts of the spacing and timing of births, and of the prior labor force attachment of the woman.